Endoluminal cardiac and venous valve prostheses and methods of manufacture and delivery thereof

ABSTRACT

This invention relates to prosthetic cardiac and venous valves and a single catheter device and minimally invasive techniques for percutaneous and transluminal valvuloplasty and prosthetic valve implantation.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a divisional of co-pending U.S. utilitypatent application Ser. No. 09/854,002, filed May 11, 2001, which is adivisional patent application of U.S. Ser. No. 09/477,120, filed Dec.31, 1999 and which has subsequently issued as U.S. Pat. No. 6,458,153 onOct. 1, 2002.

BACKGROUND OF THE INVENTION

[0002] The present invention relates generally to implantable prostheticcardiac and venous valves. More particularly, the present inventionpertains to prosthetic cardiac and venous valve implants which arecapable of being delivered using endovascular techniques and beingimplanted at an intracardiac or intravenous site without the need foranatomic valve removal. The prosthetic valves of the present inventionare well-suited for cardiac delivery via a femoral or subclavian arteryapproach using a delivery catheter, and, depending upon the specificconfiguration selected, may be deployed within the heart to repair valvedefects or disease or septal defects or disease. According to oneembodiment of the invention, there is provided a chamber-to-vessel (CV)configuration which is particularly well-suited as an aortic valveprosthesis to facilitate blood flow from the left ventricle to theaorta. In a second embodiment, there is provided a prosthetic valve in achamber-to-chamber (CC) configuration which is particularly well-adaptedfor mitral valve replacement or repair of septal defects. Finally, athird embodiment is provided in a vessel-to-vessel (VV) configuration,which is well suited for venous valve exclusion and replacement.

[0003] Common to each of the CV, CC and VV embodiments of the presentinvention are a stent support member, a graft member which covers atleast a portion of either or both the lumenal and ablumenal surfaces ofthe stent, valve flaps which are formed either by biological xenograftvalves, synthetic valves formed from either the same material or adifferent material as the graft member, the valve flaps being coupled tothe stent in a manner which biases the valve flaps so they close upon azero pressure differential across the valve region.

[0004] It is important for the present invention to provideorientational definitions. For purposes of the present invention,references to positional aspects of the present invention will bedefined relative to the directional flow vector of blood flow throughthe implantable device. Thus, the term “proximal” is intended to mean onthe inflow or upstream flow side of the device, while “distal” isintended to mean on the outflow or downstream flow side of the device.With respect to the catheter delivery system described herein, the term“proximal” is intended to mean toward the operator end of the catheter,while the term “distal” is intended to mean toward the terminal end ordevice-carrying end of the catheter.

SUMMARY OF PRIOR ART

[0005] The prior art discloses certain common device segments inherentlyrequired by a percutaneous prosthetic valve: an expandable stentsegment, an anchoring segment and a flow-regulation segment.

[0006] Prior art percutaneous prosthetic valve devices include theDobben valve, U.S. Pat. No. 4,994,077, the Vince valve, U.S. Pat. No.5,163,953, the Teitelbaum valve, U.S. Pat. No. 5,332,402, the Stevensvalve, U.S. Pat. No. 5,370,685, the Pavcnik valve, U.S. Pat. No.5,397,351, the Taheri valve, U.S. Pat. No. 5,824,064, the Andersonvalves, U.S. Pat. Nos. 5,411,552 & 5,840,081, the Jayaraman valve, U.S.Pat. No. 5,855,597, the Besseler valve, U.S. Pat. No. 5,855,601, theKhosravi valve, U.S. Pat. No. 5,925,063, the Zadano-Azizi valve, U.S.Pat. No. 5,954,766, and the Leonhardt valve, U.S. Pat. No. 5,957,949.Each of these pre-existing stent valve designs has certain disadvantageswhich are resolved by the present invention.

[0007] The Dobben valve has a disk shaped flap threaded on a wire bentlike a safety pin to engage the vessel wall and anchor the valve. Asecond embodiment uses a stent of a cylindrical or crown shape that ismade by bending wire into a zigzag shape to anchor the device and attachthe flow regulator flap. The device presents significant hemodynamic,delivery, fatigue and stability disadvantages.

[0008] The Vince valve has a stent comprised of a toroidal body formedof a flexible coil of wire and a flow-regulation mechanism consisting ofa flap of biologic material. Numerous longitudinal extensions within thestent are provided as attachment posts to mount the flow-regulationmechanism. The device requires balloon expansion to deliver to the bodyorifice. The main shortcoming of this design is delivery profile.Specifically, the device and method put forth will require a 20+ Frenchsize catheter (approximately 9 French sizes to accommodate the balloonand 14+ French sizes to accommodate the compressed device) making thedevice clinically ineffective as a minimally invasive technique.Additionally, the device does not adequately address hemodynamic,stability and anchoring concerns.

[0009] The Teitelbaum valve is made of shape memory nitinol and consistsof two components. The first component is stent-like and comprised of ameshwork or braiding of nitinol wire similar to that described byWallsten, U.S. Pat. No. 4,655,771, with trumpet like distal a proximalflares. The purpose of the stent is to maintain a semi-ridged patentchannel through the diseased cardiac valve after initial balloondilation. The flared ends are intended to maintain the position of thestent component across the valve thereby anchoring the device.Embodiments for the flow-regulation mechanism include a slidingobturator and a caged ball both which are delivered secondary to thestent portion. The disadvantages of the device are the flow regulatorsreduce the effective valve orifice and generate sub-optimal hemodynamiccharacteristics; fatigue concerns arise from the separate nature of thestent and flow-regulation components; the high metal and exposed metalcontent raises thrombogenesis, valvular stenosis and chronicanticoagulation concerns; and the separate delivery requirements(although addressing the need for small delivery profile) in addition toany initial valvuloplasty performed increases the time, costs, risks,difficulty and trauma associated with the percutaneous procedure.

[0010] The Pavcnik valve is a self-expanding percutaneous devicecomprised of a poppet, a stent and a restraining element. The valvestent has barbed means to anchor to the internal passageway. The deviceincludes a self-expanding stent of a zigzag configuration in conjunctionwith a cage mechanism comprised of a multiplicity of crisscrossed wiresand a valve seat. The disadvantages of the device include large deliveryprofile, reduced effective valvular orifice, possible perivalvularleakage, trauma-inducing turbulent flow generated by the cage occlusiveapparatus and valve seat, thrombogenesis, valvular stenosis, chronicanticoagulation, problematic physiological and procedural concerns dueto the barb anchors and complex delivery procedure that includesinflation of occlusive member after initial implantation.

[0011] Stevens discloses a percutaneous valve replacement system for theendovascular removal of a malfunctioning valve followed by replacementwith a prosthetic valve. The valve replacement system may include aprosthetic valve device comprised of a stent and cusps forflow-regulation such as a fixed porcine aortic valve, a valveintroducer, an intraluminal procedure device, a procedure device capsuleand a tissue cutter. The devices disclosed indicate a long and complexprocedure requiring large diameter catheters. The valve device disclosedwill require a large delivery catheter and does not address the keymechanisms required of a functioning valve. Additionally, the devicerequires intraluminal-securing means such as suturing to anchor thedevice at the desired location.

[0012] The Taheri valve describes an aortic valve replacement combinedwith an aortic arch graft. The devices and percutaneous methodsdescribed require puncture of the chest cavity.

[0013] Anderson has disclosed various balloon expandable percutaneousprosthetic valves. The latest discloses a valve prosthesis comprised ofa stent made from an expandable cylindrical structure made of severalspaced apices and an elastically collapsible valve mounted to the stentwith the commissural points of the valve mounted to the apices. Thedevice is placed at the desired location by balloon expanding the stentand valve. The main disadvantage to this design is the 20+ French sizedelivery requirement. Other problems include anchoring stability,perivalvular leakage, difficult manufacture and suspect valveperformance.

[0014] The Jayaraman valve includes a star-shaped stent and areplacement valve and/or replacement graft for use in repairing adamaged cardiac valve. The device is comprised of a chain ofinterconnected star-shaped stent segments in the center of which sits areplacement valve. The flow-regulation mechanism consists of three flapscut into a flat piece of graft material that is rolled to form a conduitin which the three flaps may be folded inwardly in an overlappingmanner. An additional flow-regulation mechanism is disclosed in which apatch (or multiple patches) is sutured to the outside of a conduit whichis then pulled inside out or inverted such that the patch(s) reside onthe fully inverted conduit. A balloon catheter is required to assistexpansion during delivery. The disadvantages of this design include lackof sufficient anchoring mechanism; problematic interference concernswith adjacent tissues and anatomical structures; fatigue concernsassociated with the multiplicity of segments, connections and sutures;lack of an adequately controlled and biased flow-regulation mechanism;uncertain effective valve orifice, difficult manufacture; balloondilation requirement; complex, difficult and inaccurate delivery andlarge delivery profile.

[0015] The Besseler valve discloses methods and devices for theendovascular removal of a defective heart valve and the replacement witha percutaneous cardiac valve. The device is comprised of aself-expanding stent member with a flexible valve disposed within. Thestent member is of a self-expanding cylindrical shape made from a closedwire in formed in a zigzag configuration that can be a single piece,stamped or extruded or formed by welding the free ends together. Theflow-regulation mechanism is comprised of an arcuate portion whichcontains a slit (or slits) to form leaflets and a cuff portion which issutured to and encloses the stent. The preferred flow regulator is aporcine pericardium with three cusps. An additional flow regulator isdescribed in which the graft material that comprises the leaflets (noadditional mechanisms for flow-regulation) extends to form the outercuff portion and is attached to the stent portion with sutures. Theanchoring segment is provided by a plurality of barbs carried by thestent (and therefor penetrating the cuff-graft segment). Deliveryrequires endoluminal removal of the natural valve because the barbanchors will malfunction if they are orthotopically secured to thenative leaflets instead of the more rigid tissue at the native annulusor vessel wall. Delivery involves a catheter within which the device anda pusher rod are disposed. The disadvantages of the device are lack of awell defined and biased flow-regulation mechanism, anatomic valveremoval is required thereby lengthening the procedure time, increasingdifficulty and reducing clinical practicality, trauma-inducing barbs asdescribed above and the device is unstable and prone to migration ifbarbs are omitted.

[0016] The Khosravi valve discloses a percutaneous prosthetic valvecomprised of a coiled sheet stent similar to that described byDerbyshire, U.S. Pat. No. 5,007,926, to which a plurality of flaps aremounted on the interior surface to form a flow-regulation mechanism thatmay be comprised of a biocompatible material. The disadvantages of thisdesign include problematic interactions between the stent and flaps inthe delivery state, lack of clinical data on coiled stent performance,the lack of a detailed mechanism to ensure that the flaps will create acompetent one-directional valve, lack of appropriate anchoring means,and the design requirements imposed by surrounding anatomical structuresare ignored.

[0017] The Zadno-Azizi valve discloses a device in which flow-regulationis provided by a flap disposed within a frame structure capable oftaking an insertion state and an expanded state. The preferredembodiment of the flow-regulation mechanism is defined by a longitudinalvalve body made of a sufficiently resilient material with a slit(s) thatextends longitudinally through the valve body. Increased sub-valvularpressure is said to cause the valve body to expand thereby opening theslit and allowing fluid flow there through. The valve body extends intothe into the lumen of the body passage such that increasedsupra-valvular pressure will prevent the slit from opening therebyeffecting one-directional flow. The device includes embedding the framewithin the seal or graft material through injection molding, blowmolding and insertion molding. The disadvantages of the device includethe flow-regulation mechanism provides a small effective valve orifice,the turbidity caused by the multiple slit mechanisms, the large deliveryprofile required by the disclosed embodiments and the lack of acuteanchoring means.

[0018] Finally, the Leonhardt valve is comprised of a tubular grafthaving radially compressible annular spring portions and a flowregulator, which is preferably a biological valve disposed within. Inaddition to oversizing the spring stent by 30%, anchoring means isprovided by a light-activated biocompatible tissue adhesive is locatedon the outside of the tubular graft and seals to the living tissue. Thestent section is comprised of a single piece of superelastic wire formedinto a zigzag shape and connected together by crimping tubes, adhesivesor welds. A malleable thin-walled, biocompatible, flexible, expandable,woven fabric graft material is connected to the outside of the stentthat is in turn connected to the biological flow regulator.Disadvantages of this device include those profile concerns associatedwith biological valves and unsupported graft-leaflet regulators, a largediameter complex delivery system and method which requires multipleanchoring balloons and the use of a light activated tissue adhesive inaddition to any prior valvuloplasty performed, interference withsurrounding anatomy and the questionable clinical utility andfeasibility of the light actuated anchoring means.

SUMMARY OF THE INVENTION

[0019] With the shortcomings of the prior art devices, there remains aneed for a clinically effective endoluminally deliverable prostheticvalve that is capable of orthotopic delivery, provides a mechanicallydefined, biased and hemodynamically sound flow-regulation mechanism,provides sufficient force to maintain a large acute effective valvularorifice dimension which expands to a known larger effective orificedimension, compliant with adjacent dynamic anatomical structures, doesnot require valve removal, does not require chronic anticoagulationtreatment, meets regulatory fatigue requirements for cardiac valveprostheses, provides a low-metal high-strength stent-annulus, issurgically explantable or endoluminally removable, in addition to beingable to deploy multiple valves orthotopically, provides a deliveryprofile which does not exceed the 12 French size suitable for peripheralvascular endoluminal delivery, combines anatomic valve exclusion andprosthetic valve delivery via a single catheter delivery system and withshort duration atraumatic procedure which is easy to complete andbeneficial to very sick patients.

[0020] It is, therefore, a primary of the present invention to provide aprosthetic endoluminally-deliverable unidirectional valve. The inventionhas multiple configurations to treat malfunctioning anatomical valvesincluding heart and venous valves. Prosthetic cardiac valveconfigurations include the chamber-to-vessel for orthotopic placement atthe valvular junction between a heart chamber and a vessel, and thechamber-to-chamber for orthotopic placement at the valvular junctionbetween two heart chambers or for septal defect repair where a septaloccluding member is substituted for the flow regulator valve flaps.Prosthetic venous valve configurations include the vessel-to-vessel fororthotopic or non-orthotopic placement at a valvular junction within avessel.

[0021] The invention consists generally of a stent body member, a graft,and valve flaps. The stent body member may be fashioned by laser cuttinga hypotube or by weaving wires into a tubular structure, and ispreferably made from shape memory or super-elastic materials, such asnickel-titanium alloys known as NITINOL, but may be made of balloonexpandable stainless steel or other plastically deformable stentmaterials as are known in the art, such as titanium or tantalum, or maybe self-expanding such as by weaving stainless steel wire into astressed-tubular configuration in order to impart elastic strain to thewire. The graft is preferably a biocompatible, fatigue-resistantmembrane which is capable of endothelialization, and is attached to thestent body member on at least portions of either or both the lumenal andablumenal surfaces of the stent body member by suturing to orencapsulating stent struts. The valve leaflets are preferably formed bysections of the graft material attached to the stent body member.

[0022] The stent body member is shaped to include the following stentsections: proximal and distal anchors, a intermediate annular stentsection, and at least one valve arm or blood flow regulator struts. Theproximal and distal anchor sections are present at opposing ends of theprosthesis and subtend either an acute, right or obtuse angle with acentral longitudinal axis that defines the cylindrical prosthesis. Ineither the CV or CC configurations, the proximal anchor is configured toassume approximately a right angle radiating outward from the centrallongitudinal axis of the prosthesis in a manner which provides ananchoring flange. When being delivered from a delivery catheter, theproximal anchor is deployed first and engages the native tissue andanatomical structures just proximal to the anatomic valve, such as theleft ventricle wall in the case of retrograde orthotopic delivery at theaortic valve. Deployment of the proximal anchor permits the intermediateannular stent section to be deployed an reside within the native valveannular space and the ablumenal surface of the intermediate annularstent section to abut and outwardly radially compress the anatomic valveleaflets against the vascular wall. The distal anchor is then deployedand radially expands to contact the vascular wall and retain theprosthesis in position, thereby excluding the anatomic valve leafletsfrom the bloodflow and replacing them with the prosthetic valveleaflets.

[0023] Flow regulation in the inventive stent valve prosthesis isprovided by the combination of the prosthetic valve leaflets and thevalve arms and is biased closed in a manner similar manner to thatdescribed for a surgically implanted replacement heart valve by Boretos,U.S. Pat. No. 4,222,126. The valve regulator-struts are preferablyconfigured to be positioned to radiate inward from the stent body membertoward the central longitudinal axis of the prosthesis. Thegraft-leaflet has the appearance of a partially-everted tube where theinnermost layer, on the lumenal surface of the stent body member, formsthe leaflets and the outer-most layer, on the ablumenal surface of thestent body member, forms a sealing graft which contacts and excludes theimmobilized anatomical valve leaflets. The struts of the stent areencapsulated by the outer graft-membrane. The valve regulator-struts areencapsulated by the inner leaflet-membrane and serve to bias the valveto the closed position. The regulator-struts also prevent inversion orprolapse of the otherwise unsupported leaflet-membrane during increasedsupra-valvular pressure. The inner leaflet-membrane may also be attachedto the outer graft-membrane at points equidistant from the valvestrut-arms in a manner analogous to that described for a surgicallyimplanted replacement heart valve by Cox, U.S. Pat. No. 5,824,063. Thecombination of the thin walled properties of the leaflet-membrane, theone-sided open lumen support of the intermediate annular stent section,the free ends of the valve leaflets, the biasing and support provided bythe valve regulator-struts and the attachment points all work to providea prosthetic valvular device capable of endoluminal delivery whichsimulates the hemodynamic properties of a healthy anatomical cardiac orvenous valve.

BRIEF DESCRIPTION OF FIGURES

[0024]FIG. 1 is a perspective view of the inventive valve stentchamber-to-vessel embodiment in its fully deployed state.

[0025]FIG. 2 is a perspective view of the inventive valve stentchamber-to-vessel embodiment in its fully deployed state with theoutermost graft layer and stent layer partially removed to show anembodiment of the valve apparatus.

[0026]FIG. 3 is a top view of the inventive valve stentchamber-to-vessel embodiment in its fully deployed state.

[0027]FIG. 4 shows the cross-sectional taken along line 4-4 of FIG. 1.

[0028]FIG. 5 is a bottom view of the inventive valve stentchamber-to-vessel embodiment in its fully deployed state.

[0029]FIG. 6A illustrates a cross-sectional view of a human heart duringsystole with the inventive valve stent chamber-to-vessel embodimentimplanted in the aortic valve and illustrating a blood flow vector of anejection fraction leaving the left ventricle and passing through theinventive valve stent.

[0030]FIG. 6B illustrates a cross-sectional view of a human heart duringdiastole with the inventive valve stent chamber-to-vessel embodimentimplanted in the aortic valve and illustrating a blood flow vector ofblood passing from the left atrium, through the mitral valve and intothe left ventricle during and a retrograde blood flow vector blocked bythe inventive valve stent in the aorta.

[0031]FIG. 7 is a perspective view of the inventive valve stentchamber-to-chamber embodiment in its fully deployed state.

[0032]FIG. 8 is a is a perspective view of the inventive valve stentchamber-to-chamber embodiment in its fully deployed state with theoutermost graft layer and stent layer partially removed to show anembodiment of the valve apparatus.

[0033]FIG. 9 is a top view of the inventive valve stentchamber-to-chamber embodiment in its fully deployed state.

[0034]FIG. 10 shows the cross sectional view taken along line 10-10 ofFIG. 7.

[0035]FIG. 11 is a bottom view of inventive valve stentchamber-to-chamber embodiment in its fully deployed state.

[0036]FIG. 12A illustrates a cross-sectional view of a human heartduring atrial systole with the inventive valve stent chamber-to-chamberembodiment implanted at the site of the mitral valve and illustrating ablood flow vector of a filling fraction leaving the left atrium andentering the left ventricle.

[0037]FIG. 12B illustrates a cross-sectional view of a human heartduring atrial diastole with the inventive valve stent chamber-to-chamberembodiment implanted at the site of the mitral valve and illustrating ablood flow vector of an ejection fraction from the left ventricle to theaorta and the back pressure against the implanted mitral valveprosthesis.

[0038]FIG. 13 is a perspective view of the chamber-to-vesselconfiguration in the fully deployed state.

[0039]FIG. 14 is a perspective view of the same configuration in thefully deployed state with the outermost graft layer and stent layerpartially removed to show an embodiment of the valve apparatus.

[0040]FIG. 15 is a top view of the same configuration.

[0041]FIG. 16 shows the cross sectional view of the same configurationfor the deployed state.

[0042]FIG. 17 is a bottom view of the same configuration.

[0043]FIGS. 18A and 18B show cross-sectional views of a vein and venousvalve illustrating the inventive prosthetic venous valve in the open andclosed state.

[0044]FIG. 19 is a cross-sectional diagrammatic view of a valvuloplastyand stent valve delivery catheter in accordance with the presentinvention FIGS. 20A-201 are diagrammatic cross-sectional viewsillustrating single catheter valvuloplasty, inventive stent valvedelivery and stent valve operation in situ in accordance with the methodof the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] The present invention consists generally of three preferredembodiments, each embodiment corresponding to a prosthetic stent valveconfiguration adapted for either heart chamber to blood vesselcommunication, chamber to chamber communication or vessel to vessel, orintravascular configuration. Certain elements are common to each of thepreferred embodiments of the invention, specifically, each embodimentincludes a stent body member which defines a central annular openingalong the longitudinal axis of the stent body member, a graft memberwhich covers at least a portion of the stent body member along eitherthe lumenal or ablumenal surfaces of the stent body member, at least onebiasing arm is provided and projects from the stent body member and intothe central annular opening of the stent body member, and at least onevalve flap member which is coupled to each biasing arm such that thebiasing arm biases the valve flap member to occlude the central annularopening of the stent body member under conditions of a zero pressuredifferential across the prosthesis. The stent body member is preferablymade of a shape memory material or superelastic material, such asNITINOL, but also be fabricated from either plastically deformablematerials or spring-elastic materials such as is well known in the art.Additionally, the stent body member has three main operable sections, aproximal anchor section, a distal anchor section and an intermediateannular section which is intermediate the proximal and distal anchorsections. Depending upon the specific inventive embodiment, the distaland proximal anchor sections may be either a diametrically enlargedsection or may be a flanged section. The intermediate annular sectiondefines a valve exclusion region and primary blood flow channel of theinventive valve stent. The intermediate annular section defines alumenal opening through which blood flow is established. The transversecross-section of the lumenal opening may be circular, elliptical,ovular, triangular or quadralinear, depending upon the specificapplication for which the valve stent is being employed. Thus, forexample, where a tricuspid valve is particularly stenosed, it may bepreferable to employ a valve stent with a lumenal opening in theintermediate annular section which has a triangular transversecross-sectional dimension.

[0046] Chamber-to-Vessel Configuration

[0047] An implantable prosthesis or prosthetic valve in accordance withcertain embodiments of the chamber-to-vessel CV configuration of thepresent invention is illustrated generally in FIGS. 1-5. Thechamber-to-vessel valve stent 10 consists of an expandable stent bodymember 12 and graft member 11. The stent body member 12 is preferablymade from a shape memory and/or superelastic NITINOL material, orthermomechanically similar materials, but may be made of plasticallydeformable or elastically compliant materials such as stainless steel,titanium or tantalum. The graft member 11 is preferably made ofbiologically-derived membranes or biocompatible synthetic materials suchas DACRON or expanded polytetrafluoroethylene. The stent body member 12is configured to have three functional sections: a proximal anchorflange 22, an intermediate annular section 20 and a distal anchorsection 16. The stent body member 12, as with conventional stents isformed of a plurality of stent struts 13 which define interstices 14between adjacent stent struts 13. The stent body member preferably alsoincludes a transitional section 18 which interconnects the intermediateannular section 20 and the distal anchor section 16, which togetherdefine a valve exclusion region of the inventive stent valve 10 toexclude the anatomic valve after implantation. The proximal anchorflange 22, the intermediate annular section 20 and the distal anchorsection 16 are each formed during the formation of the stent body memberand are formed from the same material as the stent body member andcomprise stent struts 13 and intervening interstices 14 between adjacentpairs of stent struts 13. The anchor flange 22, for example, consists ofa plurality of stent struts and a plurality of stent interstices, whichproject radially outwardly away from the central longitudinal axis ofthe stent body member. Thus, the different sections of the stent bodymember 12 are defined by the positional orientation of the stent strutsand interstices relative to the central longitudinal axis of the stentbody member 12.

[0048] With reference to FIG. 2, there is shown in greater detail thevalve body 26 and valve arms or flow regulator struts 24 coupled to thestent body member 12. The valve body 26 subtends the central annularopening of the stent valve 10 and is illustrated in its closed position.In accordance with one embodiment of the present invention, the graftmember 11 consists of an outer or ablumenal graft member 11 a and aninner or lumenal graft member 11 b. The outer graft member 11 a enclosesat least a portion of the ablumenal surface of the intermediate annularsection 20 of the stent body member, while the inner graft member 11 bis coupled, on the lumenal surface of the intermediate annular section20 of the stent body member 12, to the outer graft member 11 a throughthe interstices 14 of the stent body member. The valve body 26 is formedby everting the inner graft member 11 b toward the central longitudinalaxis of the stent body member 12 such that free ends or valve flapportions 28 of the inner graft member 11 b are oriented toward thedistal anchor section 16 of the stent body member 12 and a pocket orenvelope 27 is formed at the eversion point of the inner graft member 11b adjacent the junction between the intermediate annular section 20 andthe proximal anchor flange 22 of the stent body member 12.Alternatively, portions of the outer graft member 11 a may be passedthrough to the lumenal surface of the stent body member 12, therebybecoming the inner graft member 11 b and everted to form the valve body26.

[0049] Valve arms or regulator struts 24 are coupled or formed integralwith the stent body member 12 and are positioned adjacent the junctionpoint between intermediate annular section 20 and the proximal anchorflange 22 of the stent body member 12. The valve arms 24 are orientedradially inward toward the central longitudinal axis of the stent bodymember 12 when in their zero strain state. The valve arms 24 areattached or coupled to the valve flap portions 28 of the inner graftmember leaflets to bias the valve flap portions 28 to the closedposition when under zero pressure differential across the stent valve10.

[0050] The zero strain position of the valve arms 24 is radially inwardand orthogonal to the central longitudinal axis of the stent valve 10.Valve arms 24 have a length which is preferably longer than the radiusof the lumenal diameter of the stent valve 10, and they extent distallyinto the lumen of the stent valve 10 such that, in conjunction with theaction of the valve leaflets 28, the valve arms 24 are prevented fromachieving their zero strain configuration thereby biasing the valveclosed. As shown in FIG. 4, the valve arms 24 force the valve leaflets28 to collapse into the center of the lumen of the stent valve 10, thusbiasing the valve to its closed position.

[0051] It is preferable to couple sections of the valve flaps 28, alonga longitudinal seam 29, to the inner graft member 11 b and the outergraft member 11 a at points equidistant from the valve arms 24 in orderto impart a more cusp-like structure to the valve flaps 28. It should beappreciated, that the graft member 11 should cover at least a portion ofthe ablumenal surface of the stent body member 12 in order to excludethe anatomic valves, but may also cover portions or all of the stentvalve member 12, including the distal anchor section 16, theintermediate annular section 20, the transition section 18 and/or theproximal anchor flange 22, on either or both of the lumenal andablumenal surfaces of the stent body member.

[0052] In accordance with a particularly preferred embodiment of the CVvalve stent 10, the proximal anchor flange 22, which consists of aplurality of stent struts and stent interstices which project radiallyoutward away from the central longitudinal axis of the valve stent 10,is configured to have one or more stent struts eliminated from theproximal anchor flange 22 to define an open region which is positionedin such a manner as to prevent the CV valve stent 10 from interferingwith or impinging upon an adjacent anatomic structure. For example,where the CV valve stent 10 is to be an aortic valve prosthesis, it isknown that the mitral valve is immediately adjacent the aortic valve,and the mitral valve flaps deflect toward the left ventricle. Thus,placing the CV valve stent 10 such that the proximal anchor flange 22 isadjacent the mitral valve might, depending upon the particular patientanatomy, interfere with normal opening of the mitral valve flaps. Byeliminating one or more of the stent struts in the proximal anchorflange 22, an opening is created which permits the mitral valve flaps todeflect ventricularly without impinging upon the proximal anchor flange22 of the CV valve stent 10.

[0053] Similarly, the stent struts of the CV valve stent 10 may beoriented in such a manner as to create interstices of greater or smallerarea between adjacent struts, to accommodate a particular patientanatomy. For example, where the stent struts in the distal anchorsection 16 would overly an artery branching from the aorta, such as thecoronary ostreum arteries, it may be desirable to either eliminatecertain stent struts, or to configure certain stent struts to define agreater interstitial area to accommodate greater blood flow into thecoronary ostreum.

[0054] In the case of providing an oriented opening in the proximalanchor flange, or an oriented opening in the interstitial spaces of thedistal anchor, it is desirable to provide radiopaque markers on thestent body member 12 to permit the CV valve stent to be orientedcorrectly relative to the anatomic structures.

[0055]FIGS. 6A and 6B illustrate the inventive CV stent valve 10implanted in the position of the aortic valve and excluding the anatomicaortic valve AV. FIG. 6A illustrates the heart during systole in which apositive pressure is applied to the prosthetic aortic valve bycontraction of the left ventricle LV and the ejection fractionrepresented by the arrow. The systolic pressure overcomes the biasexerted by the valve arms 24 and causes the valve leaflets 26 to openand release the ejection fraction into the aorta. FIG. 6B illustratesthat the presence of a negative pressure head across the stent valve 10,i.e. such as that during diastole, causes the biased valve leaflets 26which are already closed, to further close, and prevent regurgitationfrom the aorta into the left ventricle.

[0056] Chamber-to-Chamber Configuration

[0057] FIGS. 7-11 illustrate the inventive stent valve in thechamber-to-chamber (CC) configuration 40. The CC valve stent 40 isconstructed in a manner which is virtually identical to that of the CVvalve stent 10 described above, except that the distal anchor section 16of the CV valve stent 10 is not present in the CC valve stent 40, but issubstituted by a distal anchor flange 42 in the CC stent valve. Thus,like the CV valve stent 10, described above, the CC valve stent 40 ifformed of a stent body member 12 and a graft member 11, with the graftmember having lumenal 11 b and ablumenal 11 a portions which cover atleast portions of the lumenal and ablumenal surfaces of the stent bodymember 12, respectively. The CC valve stent 40 has both a proximalanchor flange 44 and a distal anchor flange 42 which are formed ofsections of the stent body member 12 which project radially outward awayfrom the central longitudinal axis of the CC valve stent 40 at opposingends of the stent body member 12.

[0058] Like the CV valve stent 10, the lumenal graft portion 11 b iseverted inwardly toward the central longitudinal axis of the valve stent40 and free ends 28 of the lumenal graft portion 11 b to form valveflaps 26 which project distally toward distal anchor flange 42. Flowregulation struts 24 are coupled to or integral with the proximal anchorflange 44 and intermediate annular section 20 and project radiallyinward toward the central longitudinal axis of the CC valve stent 40.The valve flaps 26 are coupled to the flow regulation struts 24 and theflow regulation struts 24 bias the valve flaps 26 to a closed positionunder a zero strain load.

[0059] Like with the CV stent valve 10, it is preferable to couplesections of the valve flaps 28, along a longitudinal seam 29, to theinner graft member 11 b and the outer graft member 11 a at pointsequidistant from the valve arms 24 in order to impart a more cusp-likestructure to the valve flaps 28.

[0060] Turning to FIGS. 12A and B there is illustrated the inventive CCstent valve 40 implanted in the position of the mitral valve andexcluding the anatomic mitral valve MV. FIG. 12A illustrates the heartduring atrial systole in which a positive pressure is applied to theprosthetic mitral valve by contraction of the left atrium LA and thepressure exerted by the blood flow represented by the arrow. The atrialsystolic pressure overcomes the bias exerted by the valve arms 24 ontothe valve leaflets 26, and causes the valve leaflets 26 to open andrelease the atrial ejection fraction into the left ventricle. FIG. 12Billustrates that the presence of a negative pressure head across thestent valve 40, i.e. such as that during atrial diastole, causes thebiased valve leaflets 26 which are already closed, to further close, andprevent backflow from the left ventricle into the left atrium.

[0061] In accordance with another preferred embodiment of the invention,the CC configuration may be adapted for use in repairing septal defects.By simply substituting a membrane for the valve leaflets 26, the lumenof the stent body member 12 is occluded. The CC stent valve 40 may bedelivered endoluminally and placed into a position to subtend a septaldefect and deployed to occlude the septal defect.

[0062] Vessel-to-Vessel Configuration

[0063] Turning now to FIGS. 13-17, there is illustrated the inventivestent valve in its vessel-to-vessel (VV) valve stent configuration 50.The VV valve stent 50 is constructed in a manner which is virtuallyidentical to that of the CV valve stent 10 described above, except thatthe proximal anchor flange 22 of the CV valve stent 10 is not present inthe VV valve stent 50, but is substituted by a proximal anchor section52 in the VV stent valve. Thus, like the CV valve stent 10, describedabove, the VV valve stent 50 is formed of a stent body member 12 and agraft member 11, with the graft member having lumenal 11 b and ablumenal11 a portions which cover at least portions of the lumenal and ablumenalsurfaces of the stent body member 12, respectively. The VV valve stent50 has both a proximal anchor section 52 and a distal anchor section 54which are formed of sections of the stent body member 12 which arediametrically greater than the intermediate annular section 20 of the VVvalve stent 50. Transition sections 56 and 58 taper outwardly away fromthe central longitudinal axis of the VV valve stent 50 and interconnectthe intermediate annular section 20 to each of the distal anchor section54 and the proximal anchor section 52, respectively.

[0064] Like the CV valve stent 10, in the VV valve stent 50, the graftmember 11, particularly the lumenal graft portion 11 b or the ablumenalgraft portion 11 a, or both, is everted inwardly toward the centrallongitudinal axis of the valve stent 40 and free ends 28 of the lumenalgraft portion 11 b to form valve flaps 26 which project distally towarddistal anchor flange 42. Flow regulation struts 24 are coupled to orintegral with the stent body member at the proximal transition section58 and project radially inward toward the central longitudinal axis ofthe VV valve stent 50. The valve flaps 26 are coupled to the flowregulation struts 24 and the flow regulation struts 24 bias the valveflaps 26 to a closed position under a zero strain load. Like with the CVstent valve 10 and the CC stent valve 40, it is preferable to couplesections of the valve flaps 28, along a longitudinal seam 29, to theinner graft member 11 b and the outer graft member 11 a at pointsequidistant from the valve arms 24 in order to impart a more cusp-likestructure to the valve flaps 28.

[0065] Turning to FIGS. 18A and B there is illustrated the inventive VVstent valve 50 implanted in the position of a venous valve and excludingthe anatomic venous valve flaps VE. FIG. 18A illustrates the vein undersystolic blood pressure in which a positive pressure is applied to theprosthetic venous valve and the pressure exerted by the blood flowrepresented by the arrow. The systolic pressure overcomes the biasexerted by the valve arms 24 onto the valve leaflets 26, and causes thevalve leaflets 26 to open and permit blood flow through the prosthesis.FIG. 18B illustrates that the presence of a negative pressure headacross the VV stent valve 50, i.e. such as which exists at physiologicaldiastolic pressures, causes the biased valve leaflets 26 which arealready closed, to further close, and prevent backflow from the leftventricle into the left atrium.

[0066] The purpose of the proximal 54 and distal 52 anchor sections ofthe stent body member 12 is to anchor the prosthesis at the anatomicvessel-vessel junction, such as a venous valve, while causing minimalinterference with adjacent tissue. The intermediate annular section 20of the VV stent valve 50 excludes diseased anatomic leaflets andsurrounding tissue from the flow field. The flare angle of thetransition sections 56, 58 between the intermediate annular section 20and each of the proximal and distal anchor sections 54, 52,respectively, may be an acute angle, a right angle or an obtuse angle,depending upon the anatomical physiological requirements of theimplantation site. Alternatively, the transition sections 56, 58 may becoplanar with the proximal and distal anchor section 52, 54,respectively, thereby, eliminating any transition flare angle, dependingupon the anatomical and physiological requirements of the delivery site.

[0067] Single Catheter Valvuloplasty Stent Valve Delivery System andMethod of Delivery

[0068] In accordance with the present invention, there is also provide asingle catheter valvuloplasty and valve stent delivery system 200illustrated in FIG. 19. The objective of the single catheter deliverysystem 200 is to permit the surgeon or interventionalist topercutaneously deliver and deploy the inventive valve stent 10, 40 or 50at the desired anatomical site and to perform valvuloplasty with asingle catheter. In accordance with the preferred embodiment of thesingle catheter delivery system 200 of the present invention, there isprovided a catheter body 210 having dual lumens 212, 216. A first lumen212 is provided as a guidewire lumen and is defined by a guidewire shaft222 which traverses the length of the catheter body 210. A second lumenis an inflation lumen 216 for communicating an inflation fluid, such assaline, from an external source, through an inflation port 240 at theoperator end of the catheter 210, to an inflatable balloon 214 locatedat or near the distal end of the catheter body 210. The inflation lumen216 is defined by an annular space between the lumenal surface of thecatheter body 210 and the ablumenal surface of the guidewire shaft 222.A capture sheath 217 is provided at the distal end 215 of the catheterbody 210 and is positioned adjacent and distal the balloon 214. Thecapture sheath 217 defines an annular space about the guidewire lumen212 and the capture sheath 217 into which the stent valve 10, 40 or 50is positioned and retained during delivery. An annular plug member 220is within the inflation lumen 216 distal the balloon 214 and terminatesthe inflation lumen 216 in a fluid tight manner. Annular plug member 220has a central annular opening 221 through which the guidewire shaft 222passes. The annular plug member 220 is coupled to the guidewire shaft222 and is moveable axially along the central longitudinal axis of thecatheter 200 by moving the guidewire shaft 222. The annular plug member220 also serves to abut the stent valve 10, 40 and 50 when the stentvalve 10, 40 and 50 is positioned within the capture sheath 217. Theguidewire shaft 222 passes through the capture sheath 217 and terminateswith an atraumatic tip 218 which facilitates endoluminal deliverywithout injuring the native tissue encountered during delivery. Withthis configuration, the stent valve is exposed by proximally withdrawingthe catheter body 210, while the guidewire shaft 222 is maintained in afixed position, such that the annular plug member 220 retains theposition of the stent valve as it is uncovered by capture sheath 217 asthe capture sheath 217 is being proximally withdrawn with the catheterbody 210.

[0069] In many cases the anatomic valve will be significantly stenosed,and the valve flaps of the anatomic valve will be significantlynon-compliant. The stenosed valves may be incapable of complete closurepermitting blood regurgitation across the anatomic valve. Thus, it maybe desirable to configure the inflatable balloon 214 to assume aninflation profile which is modeled to maximally engage and dilatate theanatomic valves. For example, a tricuspid valve, such as the aorticvalve may stenose to an opening which has a generally triangularconfiguration. In order to maximally dilatate this triangular opening,it may be desirable to employ a balloon profile which assumes atriangular inflation profile. Alternatively, it may be advantageous toconfigure the balloon such that it does not fully occlude the anatomiclumen when inflated, but permits a quantum of blood flow to pass aroundthe balloon in its inflated state. This may be accomplished by providingchannels or ridges on the ablumenal surface of the balloon.Additionally, irregular inflation profiles of the balloon may facilitatecontinuous blood flow about the inflated balloon. Furthermore, it may bedesirable to configure the balloon to have an hour-glass inflationprofile to prevent migration or slippage of the balloon in the anatomicvalve during valvuloplasty.

[0070] In accordance with the present invention, it is preferable thatthe capture sheath 217 be made of a material which is sufficientlystrong so as prevent the stent valve 10, 40, 50 from impinging upon andseating into the capture sheath 217 due to the expansive pressureexerted by the stent valve 10, 40, 50 against the capture sheath.Alternatively, the capture sheath 217 may be lined with a lubriciousmaterial, such as polytetrafluoroethylene, which will prevent thecapture sheath 217 from exerting drag or frictional forces against thestent valve during deployment of the stent valve.

[0071] In accordance with the present invention, it is also contemplatedthat the position of the balloon 214 and the capture sheath 217 may bereversed, such that the balloon 214 is distal the capture sheath 217. Inthis configuration, the anatomic valve may be radially enlarged bydilatating the balloon 214, then the catheter moved distally to positionthe capture sheath 217 at the anatomic valve and deployed in the mannerdescribed above. This would also allow for post-deployment balloonexpansion of the deployed stent valve without the need to traverse theprosthetic valve in a retrograde fashion. Alternatively, the catheter200 of the present invention may be provided without a balloon 214 inthose cases where valvuloplasty is not required, e.g., where a stenoticvalve does not need to be opened such as with a regurgitating valve, andthe catheter 200 is terminated at its distal end with only a capturesheath 217, and deployment occurs as described above.

[0072] Turning now to FIGS. 20A-20I there is illustrated the sequence ofsteps in delivery of the stent valve of the present invention,valvuloplasty of the aortic valve and deployment of the stent valve atthe position of the aortic valve. The single catheter delivery system501 having a distal balloon 502 and a capture sheath 503 covering thevalve stent 10 (not shown in FIGS. 20A-B), is delivered percutaneouslyeither through a femoral or subclavian artery approach, and traversesthe aorta and is passed through the aortic valve 510 such that theballoon 503 on the distal end of catheter 501 is adjacent the aorticvalve 510 and the capture sheath 503 is within the left ventricle 504. Avalvuloplasty step 520 is performed by inflating balloon 503 to dilatethe aortic valve and deform the aortic valve flaps against the aortawall adjacent the aortic valve. After the valvuloplasty step 520,delivery of the valve stent 505 is initiated by stabilizing theguidewire shaft (not shown) while the catheter body is withdrawnantegrade relative to the blood flow until the proximal anchor flangesection of the valve stent 505 is exposed by the withdrawal of thecapture sheath 503. The distal anchor flange of the valve stent 505 isthen positioned at the junction between the aortic valve and the leftventricle at step 540, such that the distal anchor flange engages theventricular surface of the aortic valve. The valve stent is fullydeployed at step 550 by retrograde withdrawal of the catheter body 501which continues to uncover the intermediate annular section of the valvestent and release the aortic valve stent 505. at the aortic valve site510. In step 560, the valve stent 505 is completely deployed from thecatheter 501 and the capture sheath 503. The distal anchor section ofthe valve stent 505 expands and contacts the lumenal wall of the aorta,immediately distal the aortic valve, thereby excluding the aortic valveflaps from the lumen of the prosthetic aortic valve stent 505. In step570, the atraumatic tip and guidewire are retracted by retrogrademovement of the guidewire shaft of the catheter, and the catheter 501 iswithdrawn from the patient. FIGS. 20H and 201 depict the implanted valvestent 505 during diastole and systole, respectively. During ventriculardiastole 580, the left ventricle expands to draw blood flow 506 from theleft atrium into the left ventricle. A resultant negative pressuregradient is exerted across the valve stent 505, and the valve arms andvalve flaps 506 of the valve stent 505 are biased to the closed positionto prevent a regurgitation flow 507 from passing through the valve stent505 and into the left ventricle 504. During ventricular systole 590, theleft ventricle contracts and exerts a positive pressure across the valvestent 505, which overcomes the bias of the valve arms and valve flaps,which open 508 against the lumenal wall of the intermediate annularsection of the valve stent and permit the ejection fraction 509 to beejected from the left ventricle and into the aorta.

[0073] The method for delivery of the CC valve stent 40 or the VV valvestent 50 is identical to that of the CV stent 10 depicted in FIGS.20A-20I, except that the anatomical location where delivery anddeployment of the valve stent occurs is, of course, different.

[0074] Thus, while the present invention, including the differentembodiments of the valve stent, the delivery and deployment method andthe single catheter valvuloplasty and delivery system, have beendescribed with reference to their preferred embodiments, those ofordinary skill in the art will understand and appreciate that thepresent invention is limited in scope only by the claims appendedhereto.

What is claimed is:
 1. A method of endoluminally delivering a valvularprosthesis within an anatomic passageway to replace an anatomic valveusing a catheter comprised of at least two sections near the distal endof the catheter, a first section consisting of the valvular prosthesiscovered by a sheath, and a second section consisting of an inflatableballoon, comprising the steps of: passing the at least two sections ofthe catheter through an anatomic passageway so that the second sectionis passed distally through the anatomic valve such that a portion of theinflatable balloon is within the anatomic valve; contacting theinflatable balloon to a surface of the anatomic valve by inflating theinflatable balloon to dilatate the anatomic valve; positioning the firstsection within the anatomic valve for deployment of the valvularprosthesis; and withdrawing the sheath and the catheter to release thevalvular prosthesis from the sheath onto the dilatated anatomic valve tofunctionally replace the anatomic valve.
 2. The method of endoluminallydelivering a valvular prosthesis according to claim 1, wherein the firstsection resides near the distal end of the catheter and distal to thesecond section along the length of the catheter, and the passing stepfurther comprises passing the catheter along the anatomic passagewayuntil the first section passes distally through the anatomic valve. 3.The method of endoluminally delivering a valvular prosthesis accordingto claim 2, wherein the positioning step comprises withdrawing thecatheter to remove the second section away from the anatomic valve andallow the first section to reside within the anatomic valve.
 4. Themethod of endoluminally delivering a valvular prosthesis according toclaim 2, wherein the valvular prosthesis is self-expanding and hasanchoring flanges projecting substantially radially outwardly from thevalvular prosthesis and positioned at a distal end of the valvularprosthesis, and wherein the withdrawing step further comprises the stepsof: withdrawing the sheath to deploy the anchoring flanges, and engagingthe anchoring flanges to the distal end of the anatomic valve, therebypositioning the valvular prosthesis within the anatomic valve.
 5. Themethod of claim 2 wherein the catheter has a delivery profile of 12French size or smaller.
 6. The method of claim 2 wherein the catheter isfurther comprised of a guidewire shaft positioned co-axially within thecentral longitudinal lumen and an annular plug member concentricallycoupled to the guidewire shaft, and wherein the withdrawing step furtherincludes the step of maintaining the position of the guidewire shaft asthe catheter is withdrawn in retrograde fashion so that the annular plugmember maintains the position of the valvular prosthesis while deployingthe valvular prosthesis within the anatomic valve.
 7. The method ofendoluminally delivering a valvular prosthesis according to claim 1,wherein the second section resides near the distal end of the catheterand distal to the first section along the length of the catheter, andthe passing step further comprises passing the catheter along theanatomic passageway until the second section resides within the anatomicvalve.
 8. The method of endoluminally delivering a valvular prosthesisaccording to claim 7, wherein the positioning step further comprisespassing the second section distally through the anatomic valve andpositioning the first section within the anatomic valve.
 9. The methodof endoluminally delivering a valvular prosthesis according to claim 7,wherein the valvular prosthesis is self-expanding and includes anchoringflanges projecting substantially radially outward from the valvularprosthesis at a distal end of the valvular prosthesis, and wherein thewithdrawing step further comprises the steps of: withdrawing the sheathto deploy the anchoring flanges, and engaging the anchoring flanges tothe distal end of the anatomic valve, thereby positioning the valvularprosthesis within the anatomic valve.
 10. The method of claim 7 whereinthe catheter has a delivery profile of 12 French size or smaller. 11.The method of claim 7 wherein the catheter is further comprised of aguidewire shaft positioned co-axially within the central longitudinallumen and an annular plug member concentrically coupled to the guidewireshaft, and wherein the withdrawing step further includes the step ofmaintaining the position of the guidewire shaft as the catheter iswithdrawn in retrograde fashion so that the annular plug membermaintains the position of the valvular prosthesis while deploying thevalvular prosthesis within the anatomic valve.